Small cleanup (unused headers / commented code removals) (#8799)

A couple small code cleanups I came across while working on draft PR.

Authors:
  - Conor Hoekstra (https://github.com/codereport)

Approvers:
  - David Wendt (https://github.com/davidwendt)
  - Nghia Truong (https://github.com/ttnghia)
  - Karthikeyan (https://github.com/karthikeyann)
  - MithunR (https://github.com/mythrocks)
  - Devavret Makkar (https://github.com/devavret)

URL: #8799

cpp/src/copying/copy.cu

@@ -21,7 +21,6 @@
 #include <cudf/detail/iterator.cuh>
 #include <cudf/detail/nvtx/ranges.hpp>
 #include <cudf/detail/scatter.cuh>
-#include <cudf/fixed_point/fixed_point.hpp>
 #include <cudf/strings/string_view.cuh>
 #include <cudf/utilities/traits.hpp>
 

cpp/tests/strings/fixed_point_tests.cpp

@@ -217,23 +217,3 @@ TEST_F(StringsConvertTest, IsFixedPoint)
     cudf::test::fixed_width_column_wrapper<bool>({true, true, true, false, false, false, false});
   CUDF_TEST_EXPECT_COLUMNS_EQUIVALENT(*results, expected64_scaled);
 }
-
-#include <cudf/strings/convert/convert_floats.hpp>
-
-TEST_F(StringsConvertTest, FloatFixedPoint)
-{
-  using DecimalType = numeric::decimal64;
-  // using RepType     = cudf::device_storage_type_t<DecimalType>;
-  // using fp_wrapper  = cudf::test::fixed_point_column_wrapper<RepType>;
-
-  cudf::test::fixed_width_column_wrapper<double> floats(
-    {1.234E3, -876.0, 543.2, -0.12, .25, -2E-3, -.0027, 0.0});
-  auto strings_col = cudf::strings::from_floats(floats);
-
-  auto results = cudf::strings::to_fixed_point(
-    cudf::strings_column_view(strings_col->view()),
-    cudf::data_type{cudf::type_to_id<DecimalType>(), numeric::scale_type{-2}});
-
-  cudf::test::print(strings_col->view());
-  cudf::test::print(results->view());
-}